1. Field of the Invention
The present invention relates to a power supply wiring method for a semiconductor integrated circuit for providing a power supply to repeater cells inserted in wiring between the blocks. The present invention also relates to a semiconductor integrated circuit.
2. Description of the Related Art
For reducing the wiring delay of signal wiring connected between functional blocks, as shown in FIG. 12A, a repeater cell inserting method for inserting logic cells 100 and 101 into wiring between blocks is often used. When a power supply is provided for repeater cells inserted in the wiring between the blocks, for example, when the repeater cells are directly connected to a power supply provided around the functional blocks, vias are provided for connecting a power supply layer for the logic cells and a power supply layer provided around the blocks. If thus provided vias are present around the functional blocks, the wiring area is invaded, so that wiring between the blocks is difficult to perform. Therefore, usually, the repeater cells are moved inside the block as shown in FIG. 12B, or a repeater cell block 103 is made as shown in FIG. 12C.
Also, conventionally, when cells are located between blocks, power supply wiring is provided on the wiring area between the blocks, the cells are located below the power supply, and cell power supply wiring and cell ground wiring are provided to intersect the power supply between the blocks and connected to the power supply wiring between the blocks via contacts (For example see Japanese Unexamined Patent Application No. H 2000-331051).
However, the integration size of LSIs increases significantly in the present large scale miniaturization process, so that the number of repeaters inserted in the signal wiring between blocks is several thousands. If the above repeater cell inserting methods are used in such a condition, many steps are required for the process after insertion of repeater cells (moving into blocks, or making repeater blocks) Therefore, in order to reduce the LSI design period, it is required that the repeater cells can be located between functional blocks. Thus, a method of providing a power supply for repeater cells without invading the wiring area is required.